Indeed, in our parasha we are dealing with about 120 stab wounds, but 40 of them are ostensibly defensive wounds on the hands and arms. Of the many injuries to the chest area, only two were strong enough to penetrate the ribs, and they caused damage to the lungs. It is quite possible that Ben's struggle, and his defensive actions, prevented the knife, which was not particularly long, from penetrating deep into the chest, most of the time.
The struggle itself, which according to the findings of the scene inside the house was mostly standing, face to face, also negates the view of the murder as "particularly cruel." It can be assumed that for the first few minutes the deceased hoped to escape the murderous assault of his accused cousin. In other words, he was not in a state of prolonged helplessness, as was the case law cited in the examples.
In my opinion, if it had been determined, beyond a reasonable doubt, that the multiple superficial stabbings described in the Medical Institute's opinion were intended, maliciously and consciously, to cause a slow death and great suffering, it would have been possible to convict in aggravated circumstances with an alternative of "special cruelty" or "physical or mental abuse".
However, there is no evidence for this, and on the contrary, it is precisely the injuries to the neck and the slitting movements that the air conditioner saw that indicate the defendant's desire to complete the act of killing and not to prolong it. Admittedly, the case law held that cruelty is examined by the victim's suffering and not by the malice of the offender, but the defendant's awareness must be shown that he is causing a particularly cruel death, even if there is no need to do so.
It should also be remembered that during the incident, the defendant was injured in his hands, and it turned out that the finger tendons had been damaged. This damage was close to the beginning of the incident, according to the defendant's extensive blood found on the walls of the house. In other words, there is a possibility that the defendant's injury impaired his ability to use the full force of his hands, and thus his murderous plan "required" many stabbings.